Apparatus for heating localized areas of pipe

ABSTRACT

A device for heating localized areas of horizontally positioned pipe is formed in two complemental semi-annular hollow sections adapted to be fitted around the pipe, the sections being hinged together at the top to open and close with respect to a vertical diametric plane for fitting upon and removal from the pipe. A plurality of gun-type burners carried by the sections are adapted to project flame and heated products of combustion around the surface of the pipe.

United States Patent Mayo et al. 1 Dec. 4, 1973 [54] APPARATUS FORHEATING LOCALIZED 2,006,001 6/1935 Rowe et al 263/5 AREAS OF PIPE2,089,829 8/1937 Feree 263/4 UX 3,074,704 1/1963 Ronay 126/271.2A UXInventors: Frederick y Livonia, Mich; 3,525,326 8/1970 Deal 126/2712 ABilly G. Spires, Kenai, Alaska; William M. Bockelman, Livonia, MichPrimary ExaminerJ0hn J. Camby Attorney-Hamess, Dickey & Pierce [73]Assignee: Burners, Inc., Detroit, Mich.

[22] Filed: June 8, 1970 [57] ABSTRACT [21] Appl. No.: 44,427

A device for heating localized areas of horizontally positioned pipe isformed in two complemental semii annular hollow sections adapted to befitted around Fi d 126/271 2 A the pipe, the sections being hingedtogether at the top 9 66/ 5 to open and close with respect to a verticaldiametric plane for fitting upon and removal from the pipe. A pluralityof gun-type burners carried by the sections are adapted to project flameand heated products of [56] References Clted combustion around thesurface of the pipe.

UNITED STATES PATENTS 9/1942 Inskeep et al. 266/5 F 11 Claims, 13Drawing Figures PAIENTEDUEE 4% 11776.689 SHEET 10F a PATENTEU DEC 4 I973SHEET 2 OF 4 PATENTEDUEC 4 I975 3776589 SHEET u 0F 4 INVENTORS.

, %%ZAM APPARATUS'FOR HEATING LOCALIZED AREAS OF PIPE BACKGROUND OFTHE-INVENTION In the installation of pipelines composed of sections oflarge diameter pipe it is frequently necessary to heat localized areasof the pipe as for example, to preheat the abutting end .parts ofsections which are to be welded, or to stress relieve a welded area. Itis sometimes also necessary to apply heat to the pipe and/or to thesurrounding area to melt snow and ice, and/or to dry the pipe prior towelding. The overall objective of the present invention is to provideimproved apparatus for performing the indicated and any other heatingoperations which may be required on large diameter pipe. A relatedobject is to provide such apparatus which is relatively quick and easyto apply to and remove from'pipe, which is relatively simple,inexpensive, rugged, reliable, and capable of quickly delivering largeand accurately controlled volumes of heat to predetermined areas.

Other objects and advantages will become apparent upon consideration ofthe present disclosure in its entirety.

BRIEF DESCRIPTION OF THE FIGURES OF DRAWING FIG. 1 is a side elevationalview of heating apparatus constructed in accordance with the presentinvention, showing in cross-section a pipe to be heated, the heatingapparatus being suspended from a crane in open position and as itappears during its application to and removal from the pipe;

FIG. 2 is a similar view showing the heating apparatus closed around thepipe;

FIG. 3 is a side elevation on a larger scale;

FIG. 4 is a sectional elevational view taken substantially on the lineIV'IV of FIG. 3 and looking in'the direction of the arrows;

FIG. 5 is a plan view taking substantially on the line V-V of FIG. 4 andlooking in the direction of the arrows;

FIGS. 6, 7, 8 and 9 are sectional detailed views taken substantially asindicated by the lines UT-VI, VII- VII, VIII-VIII, and IX-IX of FIG. 4and looking in the direction of the arrows;

FIG. 10 is an enlarged detail elevational view of the area within thecircle designated X" in FIG. 4;

FIG. 11 is a view similar to FIG. 4 showing a modified construction;

FIG. l2is a bottom plan view of the embodiment of FIG. 11, and

FIG. 13 is a schematic diagram.

DETAILED DESCRIPTION OF PREFERRED FORMS OF THE INVENTION Our preferredheating apparatus is adapted to be handled by a conventional hoistingmeans such as a suitable mobile crane or hoist facility,diagrammatically indicated at 10 in'FIGS. 1 and 2 and having lift cableand hook means ll, 12, of conventional character. The heating apparatusconsists basically of two semi-annular sections, generally designated Aand B, the plane of separation of the annulus being diametric andvertical, the sections being hinged together at the top by hinge means17. A pipe to be heated is designated P, although it will be understoodthat other work might be involved. Typical usage might involve heatingthe abutting ends of two pipe sections prior to welding and/orsubsequent thereto to normalize of stress relieve the welded area.

Each of the sections A and B is formed of sheet steel and comprises twoflat semi-annular double-walled side panels 15 and 16 joined by weldingat their outer peripheries to a semi-cylindrical outer wall 18 which isindented inwardly from the exterior at desired areas to define pocketsfor the accommodation of burners 20 designed and positioned to projectflame and heated gases into the interior of the annular boxlikeenclosure defined by the sections and against a surrounded pipe when thesections are closed, as in FIG. 2, or to heat an area adjacent thereto,when the sections are open and positioned as depicted in FIG. 1.

In the construction shown in FIGS. 1-10, each of the sections has twoburner pockets, the four pockets being designated 21, 22, 23 and 24 andpositioned at approximately 90 from each other. The exact angularposition can of course be varied to conform to heating requirements.Except in the areas of the burner pockets, the side walls 15, 16 andperipheral wall 18 are of double thickness, a heat-resistant insulatingmaterial such as mineral wool being interposed to confine the heat. Eachburner pocket is defined by a flat axially extending radial wall 26which extends the full distance between and is welded to the interiorsof the double side panels 15 and 16, and a flat bottom wall 28, whichalso extends the full lateral distance between and is welded to theinteriors of the side panels, and which extends in a line tangent to acircle slightly greater than the circle represented by the open innerperiphery of the annulus. The outer wall 18 is interrupted in the areaoverlying each of the pockets and replaced by a removable cover 30.

The desired spacing between the side panels is maintained by suitablestruts 32, in addition to the tranverse panels 26, 28. The transversepanels 26 are provided with openings 33 through which any back pressurewithin the section beyond the panel 26, considered in the direction offlame propagation, can be relieved. A pair of liquid fuel burners 20 areprovided in each of the pockets, arranged to project flame through thewall 26 in a counterclockwise direction, as viewed in FIG. 4. Theburners are preferably of the self-generating type, designed to burnliquid petroleum gas such as propane delivered thereto in liquid form.The liquid fuel is fed through suitable piping, generally indicated at35, which is individual to the burners in each of the respectivepockets, so that the outputs of the burners can be separately controlledto enable accurate tem-' peratures to be achieved in desired areas ofthe work.

As shown schematically in FIG. 13, the control systern may comprise athermo-couple-controlled valve 71, 72, 73, 74, for regulating the fuelfeed to each burner pocket. The fuel is pumped from reservoir throughthe individual valves and via flexible supply hoses 77, 78, 79, 80, tothe burner supply-pipes 35 for the several burners. Flexible'leads81,82, 83, 84 from individual thermocouples 85, 86, 87, 88 are connectedto controlmeans which is arranged to control valves 71, 72, 73, 74respectively. The details of the control means, which may of anyknownsuitable type, do not constitute a part of our invention. The valvin'g'and valve control elements may be carried by a'suitable control cabinetor station on the mobile crane or hoist facility.

The flame and heated gases from the burners, including air drawn inthrough the openings 33, is projected substantially tangentially againstthe externalwall of a surrounded pipe and upon reaching the innersurface of the sloping wall 28 of the next burner pocket can passthrough a passage formed by a radial space 36 between the pipe and theforward edge of such panel 28 to mingle with the output of the nextburner. A portion of the products of combustion may also escape throughside orifices 38 in the walls l5, 16, such orifices being located undereach of the panels 28 close to the forward. extremity thereof. Orifices38 are preferably provided with adjustable dampers 41 to enablecontrolling the back pressure in each of the combustion quadrantsfor-maximum heat retention.

At its inner periphery each of the side panels carries an inwardlyfacing channel 40 containing an inwardly projecting compressibleinsulating and gasketing strip 42 adapted to rest against the externalwall of the pipe when the sections are closed thereabout, to confine theflame and gases to theinterior.

The apparatus is particularly useful in the construction and repair oflarge pipelines formed of large diameter pipe which is lying in ahorizontal position. In order to enable the manipulation of suchapparatus of a size and weight suitable for the indicated service, eachof the sectionsA and B has a pair of ears 42 and 43 at its topconstituting in effect upward extensions of the side panels and 16respectively and carrying pulleys 45, 46 around which sling 50 is loopedby which the apparatus may be lifted and lowered. The pulleys 46 arelocated closer to the vertical plane of the axis of hinge 17 than thepulleys 45, but are spaced substantially above the hinge line, while thepulleys 45 are substantially angularly spaced, a distance of the orderof 33+35 from the vertical plane through the hinge axis. The sling 50 istrained over the two pulleys 46, looped under and upwardly around eachof the pulleys 45, and its upper run extends upwardly from the pulleys45 to be engaged by the hook 12. The abutting edges 52 of the panelsextend upwardly from the hinge axis and angularly away from each otherwhen the sections are closed, at an angle which limits the extent ofopening of the sections to a desired angle somewhat exceeding thediameter of the pipe for which the apparatus is designed. When the slingis lifted by raising the hook from the position in which it is shown inFIGS. 2 and 4 to the position shown in FIG. 1, the sling pulls thepulleys 45 toward each other as well as upwardly, swinging the sectionsapart about the axis of hinge 17 until the opening is arrested byengagement of the edges 52, whereafter continued lifting permits thesections to be raised clear of the pipe or to any desired elevation forfurther use or movement to a new position.

Where the apparatus is being used in winter or in a cold climate, theapparatus may be used in the first in-- stance in the open position andapproximately as indicated in FIG. 1, in order to preheat a desiredarea, melt snow and ice, dry the pipe and the working region, etc.

If a welding operation is to be performed, the sections A and B may thenbe closed over the areas to be welded and employed to preheat the area,then removed to permit the welding operation, whereafter it may bereapplied to the pipe in the welded area to normalize it.

Clamping screws 56 for thermocouple sensors 85, 86, 87, 88 are providedon the sides of the channels 40 at suitable positions. At the cornersdefined by the junctures of the upper and lower ends of the innerperipheries of the side walls and the plane of separation of thesections, rollers 58 are provided journaled on the side walls on axesparallel to the axis of the system and positioned to engage the pipe toprevent any binding which might otherwise occur due to the high unitpressure and friction when such corner areas are engaged with the pipe.

In the modified construction shown in FIGS. 11 and 12, wherein partscorresponding to those of the embodiment above described are designatedby corresponding reference characters one hundred integers higher, fourburners are employed. Other than the arrangement of burners, bafilingand venting, the structure is essentially the sameas the firstembodiment and many of the parts will not require redescription.

-One burner, A, is arranged at the bottom of the left section anddischarges toward and into the right hand section. Another burner 1208is similarly located in the bottom of the right hand section dischargingtoward and into the left hand section. The burners 120A, 120B, areaxially displaced so that neither burner interferes with the dischargefrom the other. Each of the burner pockets 122 and 123, for the bottomburners 120A, 120B respectively, occupies onehalf the width of itssection; in an axial direction, and each such pocket is defined on theinner side by a central partitioning wall 201, 202. Central walls 201,202 extend to the free open ends of their respective sections and abutone another when the sections are closed, and the spaces between eachsuch wall and the sidewall 115, 116 farther from the pocket, definepassages 205, 206 through which the burner discharge flows into theother section. Passages 205, 206 are covered by the insulated outer wallportions 118, and the partitioning central walls 201, 202 are alsodouble and insulated, the burner pockets 122, 123 being open to theexterior and conforming in this and other respects to the burner pocketspreviously described. Preferably the partitioning walls and the burners120A, 1208 are inclined in an axial direction so that the burnersdischarge toward the central plane of the apparatus and to minimizeflame impingement against the partitioning walls, as shown in FIG. 12.

The discharges from burners 120A, 1208 are guided upwardly within theright and left sections respectively and under the inclined walls 128B,128A, respectively which are mounted and inclined similarly to walls 28previously described, although wall 128A inclines inwardly toward lesserradius in an upward direction and the burner 120AA is mounted on theupper side thereof and discharges in a clockwise direction while thewall 128B supports its burner 120BB to discharge counterclockwise andupwardly in the opposite angular direction. The outputs of all fourburners of this embodiment are thus all guided upwardly in the directionof natural draft. The gases from the bottom burners 120A, 120B may passinto the upper burner chambers through the radial spacing between thework and the inner edges of panels 128A, 128B. Outlet ports 138A, 1388in the upper areas of the sidewalls permit escape of the products ofcombustion. In this embodiment the upper burners 120AA and 120BB arelocated approximately on a horizontal diameter of the annulus, al-

though as noted previously the positioning of the burners can be variedin accordance with heating require ments.

This Detailed Description of Preferred Forms of the Invention, and theaccompanying drawings, have been furnished in compliance with thestatutory requirement to set forth the best mode contemplated by theinventors of carrying out the invention. The prior portions consistingof the Abstract of the Disclosure and the -Background of the Inventionare furnished without prejudice to comply with administrativerequirements of the Patent Office.

What is claimedis:

1. Means for heating localized peripheral area of pipe or the like,comprising a plurality of complemental annular segmental inwardlyopening box-like sections proportioned to closely surround the pipe, anda plurality of substantially tangentially discharging burners carried bysaid sections and arranged to discharge flame into the interior thereof,said sections having walls for guiding the flame and products ofcombustion around and close to the periphery of such a pipe,characterized by a pair of such sections, each of semi-annular form,separated upon a substantially vertical diametric axial plane,thesections being hinged together at the top and separable at thebottom, and grappling means for imposing a lifting force on each of saidsections at positions on opposite sides of the hinged position wherebythe sections may be supported in the open condition.

2. Heating means as defined in claim 1 including means for lifting andfor controlling the opening and closing movement of said sectionscomprising combined lifting and abutment ears carried at the top of saidsections, and sling means engageable with said ears for liftingandopening the same.

3. Heating means as defined in claim 1 including cable retainingmeans'carried by saidrsections at positions uniformly angularly spacedfrom the hinge axis whereby the sections may be simultaneously liftedand opened.

4. Means for heating localized peripheral area of pipe or the like,comprising a plurality of complemental annular segmental inwardlyopening box-like sections proportioned to closely surround the pipe, anda plurality of substantially tangentially discharging burners car'- riedby said sections and arranged to discharge flame into the interiorthereof, said sections having walls for guiding the flame and productsof combustion'around and close to the periphery of such a pipe,characterized by burners which are offset angularly from one another andwhich discharge toward one another in opposite angular directions, saidburners being axially displaced so that the discharges of said burnersmay pass each other in axially displaced regions.

5. Means for heating localized peripheral area of pipe or the like,comprising a plurality of complemental annular segmental inwardlyopening box-like sections proportioned to closely surround the pipe, anda pair of substantially tangentially discharging axially offset burnerscarried by said sections and arranged to discharge flame in oppositeangular directions into the interior thereof, said sections having wallsfor guiding the flame and products of combustion around and close to theperiphery of such a pipe, characterized by a pair of burners offsetaxially from each other and discharging in opposite angular directions.

6. Heating means as defined in claim 5 including wall portions spacedfrom the axial ends of said sections for guiding the discharges of saidburners past each other.

7. Heating means as defined in claim 4 including wall portions spacedfrom the axial ends of said sections for isolating the discharges ofsaid burners in the passing regions.

8. Heating means as defined in claim 5 wherein said burners are offsetaxially and angularly from one another and discharge toward one anotherin opposite angular directions whereby the discharges thereof may passone another in axially offset paths.

9. Heating means as defined in claim 5 wherein said burners are offsetangularly from one another and discharge toward one another in oppositeangular directions, said directions being axially displaced so that thedischarges of said burners may pass each other in axially displacedregions, and controllable escape openings in the side walls of sidecombustion chambers located close to said restricted areas ofcommunication.

10. Means for heating localized peripheral area of pipe or the like,comprising a plurality of complemental annular segmental inwardlyopening box-like sections proportioned to closely surround the pipe, anda plurality of substantially tangentially discharging burners carried bysaid sections and arranged to discharge flame into the interior thereof,said sections having walls for guiding the flame and products ofcombustion around and close to the periphery of such a pipe,characterized by burners arranged at angularly spaced positions in saidsections and discharging in the same angular direction into the interiorthereof and means dividing said sections into a plurality of angularlyspaced combustion areas communicating with each other through relativelyrestricted passages located at the inner periphery thereof, each of saidsections having controllable lateral vents located relatively close tosaid passages.

1 1. Heating means as defined in claim 1 wherein each of said sectionsincorporates at least one of said vents ling each vent. v

UNKTED STATES PATENT OFFICE QERTHWQATE 0F CORRECTION Patent No. 689Dated 8 4, 1973 l v fl Frederick W. Mayo et a1 It is certified thaterror appears in the 'above-identi and that said Letters Patent arehereby corrected as shown below:

fied patent Col. 1, line 44:, delete "UT-VI, and insert --VI-VI,

Col. 2, line 3, delete "of" and insert -0r". C01. 3, 11.1 16 39, delete"33+-35 and insert "33-35 Signed and sealed this 16th dayof April197L|..

(SEAL) Attest:

EDWARD MOFLETGELEEJR. C. MARSHALL DANN Commissioner of Patents Attesting Officer uscoMM-Dc 60376-P69 y u.s, aovmmzm rmm'mo omce; ma o-aae-auF ORM PO-1050 (10-69)

1. Means for heating localized peripheral area of pipe or the like,comprising a plurality of complemental annular segmental inwardlyopening box-like sections proportioned to closely surround the pipe, anda plurality of substantially tangentially discharging burners carried bysaid sections and arranged to discharge flame into the interior thereof,said sections having walls for guiding the flame and products ofcombustion around and close to the periphery of such a pipe,characterized by a pair of such sections, each of semi-annular form,separated upon a substantially vertical diametric axial plane, thesections being hinged together at the top and separable at the bottom,and grappling means for imposing a lifting force on each of saiDsections at positions on opposite sides of the hinged position wherebythe sections may be supported in the open condition.
 2. Heating means asdefined in claim 1 including means for lifting and for controlling theopening and closing movement of said sections comprising combinedlifting and abutment ears carried at the top of said sections, and slingmeans engageable with said ears for lifting and opening the same. 3.Heating means as defined in claim 1 including cable retaining meanscarried by said sections at positions uniformly angularly spaced fromthe hinge axis whereby the sections may be simultaneously lifted andopened.
 4. Means for heating localized peripheral area of pipe or thelike, comprising a plurality of complemental annular segmental inwardlyopening box-like sections proportioned to closely surround the pipe, anda plurality of substantially tangentially discharging burners carried bysaid sections and arranged to discharge flame into the interior thereof,said sections having walls for guiding the flame and products ofcombustion around and close to the periphery of such a pipe,characterized by burners which are offset angularly from one another andwhich discharge toward one another in opposite angular directions, saidburners being axially displaced so that the discharges of said burnersmay pass each other in axially displaced regions.
 5. Means for heatinglocalized peripheral area of pipe or the like, comprising a plurality ofcomplemental annular segmental inwardly opening box-like sectionsproportioned to closely surround the pipe, and a pair of substantiallytangentially discharging axially offset burners carried by said sectionsand arranged to discharge flame in opposite angular directions into theinterior thereof, said sections having walls for guiding the flame andproducts of combustion around and close to the periphery of such a pipe,characterized by a pair of burners offset axially from each other anddischarging in opposite angular directions.
 6. Heating means as definedin claim 5 including wall portions spaced from the axial ends of saidsections for guiding the discharges of said burners past each other. 7.Heating means as defined in claim 4 including wall portions spaced fromthe axial ends of said sections for isolating the discharges of saidburners in the passing regions.
 8. Heating means as defined in claim 5wherein said burners are offset axially and angularly from one anotherand discharge toward one another in opposite angular directions wherebythe discharges thereof may pass one another in axially offset paths. 9.Heating means as defined in claim 5 wherein said burners are offsetangularly from one another and discharge toward one another in oppositeangular directions, said directions being axially displaced so that thedischarges of said burners may pass each other in axially displacedregions, and controllable escape openings in the side walls of sidecombustion chambers located close to said restricted areas ofcommunication.
 10. Means for heating localized peripheral area of pipeor the like, comprising a plurality of complemental annular segmentalinwardly opening box-like sections proportioned to closely surround thepipe, and a plurality of substantially tangentially discharging burnerscarried by said sections and arranged to discharge flame into theinterior thereof, said sections having walls for guiding the flame andproducts of combustion around and close to the periphery of such a pipe,characterized by burners arranged at angularly spaced positions in saidsections and discharging in the same angular direction into the interiorthereof and means dividing said sections into a plurality of angularlyspaced combustion areas communicating with each other through relativelyrestricted passages located at the inner periphery thereof, each of saidsections having controllable lateral vents located relatively close tosaid passages.
 11. Heating means as defined in claim 1 wherein eaCh ofsaid sections incorporates at least one of said vents on each axialside, and a separate damper for controlling each vent.